UNIVERSAL CITY, Calif. � September 16, 2009 � The following are NBC primetime ratings results for September 15.

From 8-10 p.m. ET, the season premiere of NBC's "The Biggest Loser" averaged a 3.8/11 in adults 18-49 and 9.9 million viewers overall. Versus "Loser's" year-ago premiere results (3.2/9 in 18-49, 7.9 million viewers overall), last night's debut is up 19 percent in 18-49 and up 24 percent in total viewers.

These are the highest 18-49 and total-viewer results for a "Biggest Loser" fall debut since the first cycle launched on Tuesday, Oct. 19, 2004 (4.1/10 in 18-49, 9.9 million viewers overall).

In the time period, "The Biggest Loser" is #1 among the major networks in adults 18-49 and all other key demographics. From its first half-hour to its fourth, "Loser" increased its 18-49 rating by 31 percent (to a 4.2 from a 3.2) and its overall viewership by 20 percent or 1.7 million persons (10.5 million vs. 8.8 million).

"The Jay Leno Show" ranked #1 among the major networks in the time period in adults 18-49, #1 in adults 25-54 (the key demographic for late local news) and #1 in total viewers, plus most other key ratings categories. Last night's time-period competition included original programming on CBS (the "Big Brother" finale) and ABC (a Barbara Walters special on Patrick Swayze).

Versus Jay Leno's 2008-09 average at 11:35 p.m. ET on "The Tonight Show with Jay Leno," last night's telecast was up substantially in adults 18-49 (3.3 vs. 1.4), adults 25-54 (4.1 vs. 1.8) and total viewers (10.7 million vs. 5.2 million). Versus NBC's Monday-through-Friday 10-11 p.m. ET non-sports average over the prior 52 weeks, last night's telecast was also up substantially in adults 18-49 (3.3 vs. 2.2), adults 25-54 (4.1 vs. 2.7) and total viewers (10.7 million vs. 6.9 million).

NBC is #1 among the major networks for the night in 18-49, adults 25-54, total viewers and all other key ratings categories. NBC delivered its highest Tuesday 18-49 average since May 12, the night of the prior "Biggest Loser" finale.

Note that all national ratings are "live plus same day" unless otherwise indicated.

[EDITOR'S NOTE: What follows is the afternoon update with the final national Nielsen ratings.]

UPDATE: NBC PRIMETIME RATINGS RESULTS FOR SEPT. 15, 2009

UNIVERSAL CITY, Calif. � September 16, 2009 � The following are updated NBC primetime ratings results for September 15.

From 8-10 p.m. ET, the season premiere of NBC's "The Biggest Loser" averaged a 3.8/11 in adults 18-49 and 9.9 million viewers overall. Versus "Loser's" year-ago premiere results (3.2/9 in 18-49, 7.9 million viewers overall), last night's debut is up 19 percent in 18-49 and up 25 percent in total viewers.

These are the highest 18-49 and total-viewer results for a "Biggest Loser" fall debut since the first cycle launched on Tuesday, Oct. 19, 2004 (4.1/10 in 18-49, 9.9 million viewers overall).

In the time period, "The Biggest Loser" is #1 among the major networks in adults 18-49 and all other key demographics. From its first half-hour to its fourth, "Loser" increased its 18-49 rating by 28 percent (to a 4.1 from a 3.2) and its overall viewership by 21 percent or more than 1.8 million persons (10.6 million vs. 8.7 million).

"The Jay Leno Show" ranked #1 among the major networks in the time period in adults 18-49, #1 in adults 25-54 (the key demographic for late local news) and #1 in total viewers, plus most other key ratings categories. Last night's time-period competition included CBS's "Big Brother" finale and ABC's rebroadcast of the Barbara Walters special on Patrick Swayze, featuring new material.

Versus Jay Leno's 2008-09 average at 11:35 p.m. ET on "The Tonight Show with Jay Leno," last night's telecast was up substantially in adults 18-49 (3.4 vs. 1.4), adults 25-54 (4.2 vs. 1.8) and total viewers (11.1 million vs. 5.1 million). Versus NBC's Monday-through-Friday 10-11 p.m. ET non-sports average over the prior 52 weeks, last night's telecast was also up substantially in adults 18-49 (3.4 vs. 2.2), adults 25-54 (4.2 vs. 2.7) and total viewers (11.1 million vs. 6.9 million).

NBC is #1 among the major networks for the night in 18-49, adults 25-54, total viewers and all other key ratings categories. NBC delivered its highest Tuesday 18-49 average since May 12, the night of the prior "Biggest Loser" finale.